Laminated core for electrical apparatus



Sept. 6, 1938. R, POHL LAMINATED CORE FOR ELECTRICAL APPARATUS FiledFeb. 5, 1937 Inventor: Robjt I h| y W I 17 His Attorney.

Patented Sept. 6, 1938 UNITED STATES PATENT OFFMZE LAMINATED CORE FORELECTRICAL APPARATUS Robert Pohl, Berlin, Germany, assignor to GeneralElectric Company, a corporation of New York Application February 3,1937, Serial No. 123,791 In Germany July 1'7, 1936 2 Claims. (Cl.171252) My invention relates to improvements in lamifound that whentransversely extending radial air nated cores for electrical apparatus,and particupassages are formed in a core, and communicate larly toventilated laminated core structures for with longitudinally extendingaxial passages, the dynamo-electric machines. cooling medium, such asair, produces eddy cur- An object of my invention is to provide an rentsand restriction at the place Where the twoimproved and simplifiedventilated laminated core passages meet, thus reducing the effectivenessstructure for electrical apparatus. of the ventilating arrangement. Inorder to Further objects and advantages of my invenavoid this condition,I provide longitudinally tion will become apparent from the folowingdeextending axial passages 24 formed by a plurality scription referringto the accompanying drawof holes in the laminations of the core arrangeding, and the features of novelty which characterin registering relation,and provide a series of ize my invention will be pointed out withpartransverse radially extending passages 25 which ticularity in theclaims annexed to and formcommunicate with the passages 24 intermediateing a part of this specification. the ends thereof. The openings in thelamina- For a better understanding of my invention, tions are arrangedin stepped relation adjacent reference is made to the accompanyingdrawing, each side of the communication of the longiwherein the singlefigure is a side elevational tudinally extending passages 24 and thetransview in partial section of a dynamo-electric maverse passages 25,and these openings, which are chine embodying my invention. arranged instepped relation, are formed of in- Referring to the drawing, I haveshown a dynacreasingly larger size and arranged in increasing- 20mo-electric machine provided with a rotatable ly larger steps from thelongitudinally extending member having a laminated core I0 supported onpassage towards the transverse passage, thereby the shaft H. Thelaminations of the core I!) forming outwardly extending curved portionsare held in assembled relation by clamping rings flared toward the pointof communication be- I2 and i3 which support the end turns of an tweenthe longitudinally extending and trans- 25 electrical winding I4. Eachend of the rotatable verse passages. The rotatable member also is memberis provided with a fan I5, which is arprovided with a radially extendingventilating ranged to circulate a cooling medium, such as passage 26,and when the dynamo-electric maair, through the dynamo-electric machine.chine operates, the fans [5 blow air, as indicated A Stationary ber forthe dynamo-electric by the arrows on the drawing, through the venti- 30machine also is provided, having end shields l6 lating passages 24, 25,and 26, and the air gap enclosing ends of the rotatable member and 21between the rotatable and stationary members forming an air deflectingcompartment about the of the dynamo-electric machine. In this manner,stationary member so as to direct the cooling air th ir passing fr m theaxial passages 24 int 5 through the machine. The end shields [6 aresethe radial passages 25 tends to flow in a radial cured to a frame II,which is provide-d with a direction into the ventilating passage 25smoothplurality of circumferentially ex nding plates ly and withoutinterference with the radially [8 connected together by cross ties I9welded flowing air entering this passage from the rotatt0 the plates TheStatiOnarY member of the able member or from the air gap. This directiondynamo-electric machine is provided with a core of flow of air from thetwo sides of the longi- 40 formed by an assembly of laminations 20 se--tudinally extending passages also minimizes turcured together byclamping covers 2i and bolts bulence due to opposing air currentsentering the 22 extending through the laminations. An elecradial passagefrom the two longitudinally extrical winding 23 is arranged in slotsformed in tending passages on each side of the radial pasthe laminatedcore of the stationary member to sage. By varying the progressivestepped rela- 45 co-operate electro-dynamically with the rotattion ofthe registering openings in the laminaable member ID. tions which formthe curved portion of the In electrical apparatus, it has been founddelongitudinal passages, and by varying the size of sirable to cool thecore of the apparatus, as the these openings, any desired curvature andflaring heating of a machine generally is the limiting of the airpassage can be obtained. This arrange- 50 factor in determining itscapacity. In order to ment may be utilized in the assembly oflaminaproperly cool dynamo-electric machines, varitions forming the coreof the rotatable member, ous arrangements of passages formed in the coreas Well as in the stationary member. of the apparatus for conducting. acooling medium While I have illustrated and described a partherethroughhave been devised. It has been ticular embodiment and application of myin 55 vention, modifications thereof will occur to those skilled in theart. I desire it to be understood, therefore, that my invention is notto be limited to the particular arrangement disclosed, and I intend inthe appended claims to cover all modifications which do not depart fromthe spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. A dynamo-electric machine having a core formed of an assembly oflaminations, means including openings formed in said laminationsarranged in registering relation to provide a longitudinally extendingpassage through said core for conducting a cooling medium therethrough,a transverse passage communicating with said longitudinally extendingpassage, said openings in said laminations being arranged in steppedrelation adjacent the junction of said transverse passage and saidlongitudinally extending passage forming an outwardly curved portion toprovide for smooth flow of cooling medium from said longitudinallyextending passage into said transverse passage, and said openingsarranged in stepped relation being of increasingly larger sizes andarranged in increasingly larger steps toward the junction of saidlongitudinally extending passage and said transverse passage.

2. A dynamo-electric machine having a core formed of an assembly oflaminations, means including openings formed in said laminationsarranged in registering relation to provide longitudinally extendingpassages through said core for conducting cooling medium therethrough,transverse passages formed in said core communicating with saidlongitudinally extending passages intermediate the ends of saidtransverse passages, said openings in said laminations being arranged instepped relation adjacent each side of the junction of said transversepassages and said longitudinally extending passages forming outwardlycurved portions to provide .for smooth flow of cooling medium from saidlongitudinally extending passages into said transverse passages, saidopenings arranged in stepped relation being of increasingly larger sizeson each side towards the junction of said longitudinally extendingpassages and said transverse passages and arranged in increasinglylarger steps toward the junction of said longitudinally extendingpassages and said transverse passages.

ROBERT POI-IL.

